Nibbling tool



Feb. 20, 1951 A. F. ADEL 2,542,103

NIBBLING TOOL Filed Jan. 19, 1949 Patented Feb. 20, 1951 UN I TED STATESPATEN T O FF ICE 'NIBBLING 'TOOL Alf F. Adel, Chicago, Ill.

Application January 19, 1949, Serial No. 71,753

(Cl. 3.0--24.l-)

-8 Claims. 1

This invention rel-ates to improvements in nibbling tools and itconsists of the 'matters *herein4 after described and more particularlypointed out in the appended claims.

One of the objects of the .present inventionv is to provide a simple andefficient tool, .which may be held in and Operated by one hand, forenlarging or changing the shape of a previously formed opening Or formakinga recess in a margin of a piece of sheet material, by cutting awaychips from the periphery of .said opening or from said margin.

Another object of the invention is .to provide 'a tool of this kindWhich is easy to manipulate with rapidity without tiring the Operator's.hand and Which clears itself' of chips :so that it will not be cloggedthereby and become hard to operate.

A further object of the invention is to provide a tool of this kind thatincludes an inexpensive but strong and rigid rame, which has a good"feel' in the hand of the operator and which carries a member so mountedtherein, for actuating the movable Cutter bar, as to afford a maximum ofleverage and Whereby much thicker material may be operated upon thanwith tools heretofore made for a similar purpose.

Again it is an object of the invention to provide in a tool of 'thiskind, -a novel movable Cutter bar, which afiords an easy cutting as Wellas a clearing of the chips produced -in the operation of the tool.

The above mentioned Objects of the invention, as Well as others, alongwith 'the advantages thereof, Will more fully appear as theSpecification proceeds.

In the drawing:

Fig. 1 is a view partly in side elevation and partly in longitudinalsection -of a nibbling tool embodying the preferred form of theinvention.

Fig. 2 is a View in front elevation of the tool appearing in Fig. 1.

Fig. 3 is a horizontal detail sectional view through a part of the tool,as taken on the 'line 3-3 of Fig. 1.

Fig. 4 is another horizontal detail sectional view through a part of thetool as taken on the line 4-4 of Fig. 1.

Fi 5 is a View in front elevation of the 'movable Cutter bar of thetool, on aLsCale larger than that of Fig. 1.

Fg. 6 is a view in 'side 'elevatio'n 'of the 'Cutter bar of Fig. 5.

Fg. 7 is a top plan view .of the Cutter bar 'appearing-in Figs. 5 and 6.

Fig.'8 is a perspective View of a Chip stripper embodied in the tool Ona Scale enlarged over that of Figsil and.2.

The improved tool .in its preferred form includes among the .partsthereof an elongated frame member IH made from a strip of sheet metalbent upon itself to provide a pair of spaced side walls l-| l 'andaback1 2, joining like edges of said sides so 'that said frame member 'has are'la'tively deep channel cross section and is open at its front whichis indicated at in Fig. 1.

Between and suitably fixed to the upper end of the side walls l --ii ofthe frame, is a fiXed :cutter bar M that inclines upwardly andrearwardly toward the top end of said side walls to form .a stationarycutting edge l5, spaced about midway between the front and the back ofthe frame.

16 indicates the movable Cutter bar of the .tool and which best appearsin Figs. 5 and 6. It 'is made -of a piece of squared stock of a lengthapproximating tha-t 'of the frame and has a width and thicknesscorresponding to the distance 'between the side walls of the frame so asto fit therebetween and engage against the back |2. The front face of'this Cutter bar is disposed substantially in the plane of the cuttingedge l and a rivet a passes through the side walls 'H-ll of the frame atone side of the Cutter bar 16. This rivet 'assists in so holding theCutter bar in position and perrnits longitudinal sliding movement of'the Cutter bar in the frame.

In opposite sides of the Cutter bar I'S, toward the bottom end "thereof,are recesses H Which leave a 'central Web portion 18 in this part of thebar. At the bottom extrem'ity of the 'bar is a stud [9 adapted forengagement by one end of a coiled expansion spring za (see Fig. 1 theother end of which engages a ledge 'Zl turned in-wardly from the lower.end of the back. This spring normally urges the Cutter bar :e upwardlyto its normal position, between nibbling strokes of the same.

'The upper portion of the Cutter 'bar has parts removed from the frontand sides thereof to form Chip clearance recesses 22 and 23-43respectively Which best appear inFigs. ;5 .and *6. The upper edge 24 ofthe recess 22 is inclined and Constitutes the 'front Cutting 'edge of.the bar, which coacts, ina nibbling operation, With the cutting .edgeIS before mentioned. The upper edge 25 of the recesses 23-23 .extenclsat a right angle to 'the 'side faces of the bar and coa'ct with thesides of :the :frame as a cutting ,edge which produces the end .cuts ofthe 'chips 'produced in the operationof 'the LtOOI. I he sidefacesrZG-.ZG .of

3 that portion of the bar above the edges 25-25 taper inwardly andupwardly to the extremity of the bar, as best appears in Fig. 5. Risingcentrally from said extremity is a stud 21 that has an annular groove 28at the top, as appears in Fig. 6.

Operatively engaged upon the upper end of the bar |6 is a Chip stripper29 that best appears in perspective in Fig. 8, on the Scale of Figs and6. This stripper has a top 30 in which is a hole Sl for the passage ofthe stud 21 therethrough. Depending from each side of said top is a Chipengaging arm 32 and these arLms are so spaced apart as to engage theside cutting edges -25. A spring 33 is engaged upon the stud 27 andbears at one end upon the top of the stripper and bears at the other endagainst an annular member 34 engaged in the groove 28 in the stud 21.This spring normally urges the top of the stripper into engagement withthe top end of the bar but said spring will permit said stripper toyield upwardly as the side arms 32 thereof engage the top edges of theside walls li of the rame lt in a nibbling operation.

Associated with the open front 13 of the frame is a lever 35 preferablymade of die formed sheet metal and which includes a relatively longpower arm 36 and a short load arm 31, the lever being mounted at a pointbetween the two arms upon a pivot rivet 38 (see Fig. 1) connecting thebottom end portions of the two sides l l-ll of the frame together. Atleast the lower end of the lever is biiurcated so that the two sidesthereof straddle the web IS of the Cutter bar and at the inner end ofeach of the two sides of the load arm are recesses that provide rightangled shoulders 43 and Ali respectively, which best appear in Fig l.The shoulders :to each engage the bottom edge of the associated recessl'l in the Cutter bar IS and the shoulders ll of both load arms engagethe front face of the Cutter bar lt below said recesses to function as astop for the outward sWinging movement of the lever as a whole.

The lever arm 36 carries a stud 42 for engagement with the bar IS tolimit the swinging movement of the lever arm toward the open front ofthe rame and whereby the fingers of the operator cannot be pinchedbetween the frame and the lever in a nibbling operation of the tool.

On the upper portion of the back l2 of the frame is provided a strip ofU-shaped metal 43, the upper end of which is flared rearwardly tooverhang the crotch of the hand between the thumb and index finger whenthe tool is gripped in one hand for a nibbling operation.

As is obvious from Fig. 1, the back of the fixed Cutter bar M and thefront face of the bar 16 at the recess 22, flare downwardly and thisprovides a throat Or passageway 44 for a free discharge of the chipsformed in a nibbling operation, as the cutting edge 24 passes thecutting edge IS. It is pointed out, at this time, that as the Cutter bar16 moves downwardly in a cutting operation, one end of the edge 24 firstcoacts with the edge l and then successive portions of the edge 26 sweepacross the edge so that said edges coact to produce a true shearingaction on the sheet material being Operated upon.

Assume that a hole in a piece of sheet metal is to be enlarged orchanged in shape. Said hole is first provided by drilling the sheetmetal to a diameter to permit the passage of the upper part of 'the barIS therethro-ugh, until the metal engages with the top end of the frame.

At this time, the cutting edge 25 of the bar s disposed slightly abovethe sheet metal. By grasping the tool, with the crotch of the handengaged with the Strip 43 and With the fingers engaged with the powerarm 36 of the lever 35, the latter is swung toward the frame clockwiseas in Fig. 1. In the movement of the lever, the load arm 31 thereofSwings downwardly and due to the engagement of the shoulders til thereofwith the bottom edges of the recesses H, the Cutter bar IG is' movedlongituciinally downward in the nibbling stroke. In this downwardmovement of the bar, the cutting edges 15 and M, along with the cuttingedge 25 coact to cut away a Chip from the sheet metal, having a widththat equals the width and depth of the ,cutting edge 2 1 and this Chipdischarges downwardly through the passageway M between the bars l l and15. Also in this downward movement of the bar it the stripper 29 movesrelatively toward .the part thereby Cornpressing the spring 33 until thestud 42 O-n the lever arm 35 engages the bar 3 which acts as a stop forthe lever.

When the grip on the lever is released, the spring 20 returns the bar land lever 35 to normal position for another ni bling stroke of theCutter bar and the spring 33 returns the stripper 29 to normal positionand in such movement strips the removed metal Chip should it adhere tothe Cutter bar.

The tool may also be used in producing a recess in a margin of the sheetmetal. To do so the tool is moved toward the edge of the sheet metalwith the top end of the frame engaged with theunder side thereof and, atwhich time, the edge of the sheet metal will be engaged with the face ofthe recess 22 and a marginal part Will be overhung by the cutting edge24. By alternately swinging the lever arm 36 toward the frame and thenreleasing the same, successive nibbling strokes are produced for the barlt so that chips are nibbled or cut from said sheet metal.

The tool is of a simple, inexpensive, though strong construction andoperates easily and efliciently for its intended purpose.

While in describing this invention, I have reerred in detail to theform, arrangement and construction of the parts of which the tool ismade, the same is to be considered Only in the illustrative sense, andtherefore, I do not wish to be limited thereto except as may bespecifically set forth in the appended claims.

I claim as my invention:

1. hand operable nibbling tool embodying there1n an elongated framehaving spaced walls and open along one side, means at one end of theframe and supported from said walls and there providing a stationarycutting edge extend ing between said walls, a Cutter bar mounted in saidframe between said spaced walls for guided longitudinal nibbling andreturn strokes'from and back to a normal position, means carried by saidCutter bar and providing a movable cutting edge for cooperating withsaid stationary cutting edge in the nibbling stroke of said bar, a leverpivotally mounted on the frame and having a portion disposed between thewalls of the frame and directly engaged with a part on the Cutter barfor imparting the nibbling stroke thereto when said lever is swungtoward the open side of the frame, and means carried by said frame anddisposed between the walls thereofor imparting the'return stroke to saidCutter bar back to normal position after a nibbling stroke..

2. A hand operable nibbling tool embodying therein an elongated framehaving spaced walls and open along one side, means at one end of thebody and supported from said walls and there providing a stationarycutting edge extending between said walls, a Cutter bar mounted in saidframe between said walls for guided longitudinal nibbling and returnstrokes from and back to a normal position, means carried by said barand providing a movable cutting edge for cooperating with saidstationary cutting edge in the nibbling stroke of said bar, said barhaving recesses in opposite sides thereof, a lever pivotally mounted onthe frame and including a power arm and a load arm, the latter arm beingformed to engage in said recesses for imparting the nibbling stroke tothe cutter bar when said power arm of the lever is swung toward saidframe, and means carried by said frame and disposed between the wallsthereof and engaged with said Cutter bar for imparting the return stroketo said bar back to normal position after a nibbling stroke.

3. A hand operable nibbler embodying therein an elongated frame of achannel cross section and including laterally spaced sides joinedtogether at the back and open at the front, means extending between saidsides providing a stationary cutting edge at the top of said frame, aCutter bar member in said frame and having guided engagement with saidsides and back for longitudinal nibbling and return strokes from andback to a normal position, means carried by said bar member andproviding a movable cutting edge for cooperating with said stationaryedge in the nibbling stroke of the bar member, a lever member includinga relatively short load arm disposed between said sides of the bottom ofthe frame and a longer lever arm outside the open front of the frame,means for pivotally connecting the load arm of said lever to the sidesof the frame, means carried by said bar member and Operatively engagedby the load arm of the lever member for imparting the nibbling stroke tosaid bar member when said bar member is swung toward the open front ofthe frame, and means carried by said frame between the sides thereof andengaged with one of said members for imparting the return stroke to saidbar member to said normal position after a nibbling operation.

4. A hand operable nibbler embodying therein, an elongated frame, astationary cutting edge at one end of the frame, a Cutter bar membermounted on said frame for guided longitudinal nibbling and returnmovement from and back to a normal position, means providing a cuttingedge on said Cutter bar member and spaced outwardly from said stationarycutting edge when said Cutter bar member is in said normal position,means carried by said frame and engaged with the Other end of saidCutter bar member for imparting the nibbling and the return strokes tosaid Cutter bar member, and a stripper device mounted on and capable ofa yielding guided movement longitudinally of the Cutter bar member,toward and away from the cutting edge thereon.

5. In a hand operable nibbler including an elongated frame having spacedsides, a closed back and an open front, a bar fixed between said sidesat the top end of the frame and forming a transverse stationary cuttingedge between said closed back and said open front of the frame, a Cutterbar disposed in said frame between said Closed back and said stationarycutting edge and longitudinally movable from a normal position thereinin the nibbling stroke of the Cutter bar, said Cutter bar having alongitudinal portion of its front Cut away to form a cutting edge forcooperation with and normally disposed above said stationarycuttingedge, said cut away portion of said Cutter bar and said first mentionedbar coacting to form outwardly and downwardly fiaring passageway forchips produced in a nibbling Operation.

6. In a hand operable nibbler including an elongated frame having spacedsides, a closed back and an open front, a bar fixed between said sidesat the top end of the frame and forming a transverse stationary cuttingedge between said closed back and said open front of the frame, a Cutterbar disposed in said frame between said closed back and said stationarycutting edge and longitudinally movable from a normal position in thenibbling stroke of the Cutter bar, said movable Cutter bar being formedtowards its upper end with recessed portions providing a front cuttingedge and side cutting edges, the side portions of the bar above the sidecutting edges tapering upwardly and inwardly toward the top extremity, astud rising from said extremity, a chip stripper disposed upon said studand including side arms operatively associated with the said sideportions of the bar above said side cutting edges, and yielding meanscarried by said stud and engaged with said Strip chipper.

7. In a nibbler, a Cutter bar comprising an elongated member having arecess in the front portion thereof and a recess in each side portionthereof, said recesses each being defined at the top by a cutting edge,those portions of the member above the recesses in the sides thereoftapering upwardly and inwardly from the cutting edges defined by saidlast mentioned recesses.

8. In a nibbler, a Cutter bar comprising an elongated member having arecess in the front portion thereof and a recess in each side portionthereof, said recesses each being defined at the top by a cutting edge,those portions of the member above the recesses in the sides thereoftapering upwardly and inwardly from the cutting edges defined by saidlast mentioned recesses, the cutting edges at the top of the recess inthe front of said member, extending at an angle less than a right angleto the length of said member.

ALF F. ADEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,114,753 Waner Apr. 19, 1938FOREIGN PATEN'I'S Number Country Date 12,723 Great Britain May 11, 1905

